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The foam metal, possessing a remarkable skeletal framework, exhibits outstanding specific strength and stiffness, in conjunction with excellent thermal conductivity. Its spatially continuous porous structure not only promotes the infiltration of phase change materials but also renders it an extraordinary enhancer of thermal conductivity within phase change energy storage systems. In order to comprehensively explore the influence of copper foam structure on the heat transfer characteristics of phase change materials, this study constructs a series of structural models of copper foam frames with diverse configurations. By leveraging the finite element analysis approach, it meticulously simulates the melting processes of five unique composite copper foam structures, namely Kelvin, Gyroid, IWP, Primitive, and Hollow hexahedral. Through a detailed analysis of thermal conductivity associated with each structural model, as well as the flux variation and average temperature under a constant flow, the study scrutinizes the heat transfer properties of these disparate structures. The obtained results will provide substantial theoretical support for the optimization design of heat transfer performance in phase change heat storage systems. The results indicate that the effective thermal conductivity of MFPCMs largely depends on the structural type and its unique configuration, rather than just the porosity of the structure. Under isothermal conditions, using the melting time of the Kelvin model as a baseline, the melting time of the PCM in the Gyroid structure was reduced by approximately 20.9%, the IWP structure by 3.8%, the Primitive structure by 28.6%, and the hollow hexahedral structure by 29.9%. Under constant heat flux conditions, the melting time of the phase change material does not depend on the type of metal foam structure. The heat transfer performance of the other structures is all superior to that of the Kelvin structure. At around 150 s, all structures had their PCM completely melted, at which point the highest temperature was observed in the MFPCM based on the primitive structure, and there may be potential for further temperature increase if further studies are conducted. Therefore, these new structures hold broad application prospects in phase change energy storage systems. [ABSTRACT FROM AUTHOR]

An analytical solution is conducted on forced convection in a metal foam partially filled plate channel under asymmetric heat flux conditions, with the aim of optimizing heat transfer performance. The Darcy–Brinkman model and the local thermal non-equilibrium (LTNE) model are employed to predict heat transfer characteristics under varying heat flux ratios (q1/q2). Key parameters such as the free zone height, pore density, and thermal conductivity ratio significantly influence heat transfer efficiency. The results indicate that the height of the free region has a greater impact on the flow distribution than porosity and pore density. When the non-dimensional height of the free region is 0.3, the flow fraction in the free region reaches 80%. When the free zone height is H = 0.1, the heat exchanger heat transfer coefficient reaches its maximum value, and the combination of copper (Cu) and R134a refrigerant demonstrates superior convective heat transfer performance compared to the empty channel. Their optimization can lead to substantial improvements in the heat transfer effectiveness of the channel. [ABSTRACT FROM AUTHOR]

Metal foams are highly useful in industries because of their lightweight, energy and vibration absorption properties. This study investigated the propagation of torsional waves in an elastic layer over a fluid-saturated fractured poroelastic half-space with a metal foam coated layer. It is assumed that the interfaces are in sliding contact with two different sliding parameters. The coated layer is closed-cell aluminium foam. We use the separation variable technique and the Bessel function to solve the equation of motion in different layers. The displacement components are written in terms of the second kind Whittaker functions. Using an asymptotic formulation of the Whittaker function and appropriate boundary conditions, the dispersion equation is derived in terms of the determinant. The control of the vibration due to the metal foam-coated layer is one of the important goals of this study. Also, numerical and graphical analyses have been done with the help of Mathematica software to see the effect of different parameters on torsional wave propagation. It is found that the presence of coated metal foam layer decreases the phase velocity of the torsional wave propagation. The work may be helpful in the seismology, automobile, and aerospace industries. [ABSTRACT FROM AUTHOR]

Graphene platelets (GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams. Further bonding piezoelectric actuator and sensor layers on the surfaces of GPLs-reinforced metal foam beams enables active vibration control, greatly expanding their applications in the aerospace industry. For the first time, this paper investigates the vibration characteristics and active vibration control of GPLs-reinforced metal foam beams with surface-bonded piezoelectric layers. The constant velocity feedback scheme is used to design the closed-loop controller including piezoelectric actuators and sensors. The effects of the GPLs on the linear and nonlinear free vibrations of the beams are numerically studied. The Newmark-β method combined with Newton's iteration technique is used to calculate the nonlinear responses of the beams under different load forms including harmonic loads, impact loads, and moving loads. Additionally, special attention is given to the vibration reduction performance of the velocity feedback control on the responses of the beam. [ABSTRACT FROM AUTHOR]

Dibenzyltoluene/perhydro-dibenzyltoluene (H0DBT/H18DBT) is considered a promising liquid organic hydrogen carrier (LOHC) pair for the storage and transportation of green hydrogen (H2). However, at the point of use, the catalytic dehydrogenation of H18DBT is still limited by mass transport limitations. To address this issue, the dehydrogenation of H18DBT was successfully conducted on Pt/Al2O3-coated foams in both an unstirred tank reactor and a fixed-bed reactor (FBR). A performance comparison between coated foams and pellets in the tank reactor revealed that H2 productivities were 12–59% higher in the foam-based reactor than in the pellet-based reactor. Since the textural properties of the foam-supported and pellet-based catalysts were similar, the higher degree of dehydrogenation (DoD) and H2 productivity achieved by the former were attributed to the geometric properties of the foam structure. Long-term tests performed in the FBR demonstrated the ability of the coated foams to maintain steady activity for >16 h on stream. However, the single-pass DoDs achieved were 34–38%. By recycling the partially dehydrogenated products three times into the FBR, the DoD improved to 63%. The results of this study demonstrated the capabilities of the coated foams in the process intensification of LOHC dehydrogenation reactors. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve heat dissipation performance of panel-type radiator for transformers, this study investigated the flow and heat transfer characteristics in the air-side metal foam partially filled channels of the radiator. The porous thin-layer filled (PTLF) and porous fin filled (PFF) methods and the filling ratio (V p) were analyzed and compared. The result indicated that the permeability and interfacial turbulent kinetic energy in the porous region of PFF channel are higher. Increasing V p can promote flow mixing and heat transfer. For Re = 5,125–15,375, when V p = 11.1%, the performance evaluation criterion in PFF channel can increase by 12.0–30.8% as compared with PTLF channel. Then, the effects of metal foam material, porosity (φ), and pore density (ω) were explored. The results show that decreasing φ, increasing ω, and using copper metal foam are all beneficial for enhancing the heat transfer performance of the PFF channel within the range studied. Finally, when V p = 11.1%, the PFF channels filled with Cu-10-9.5 and Al-10-9.7 samples were selected for comparison with previous related studies, which demonstrated the feasibility of the metal foam partial filling method on the air side of the panel-type radiator.

Improvements in heat transfer performance and efficiency through a single heat transfer enhancement technology are limited. Hence, composite-enhanced heat transfer technologies must be developed to improve resource utilization rates and reduce energy consumption and carbon emissions. Refrigerants exhibit physical properties that significantly affect the energy transport in refrigeration systems. Based on the development trend of refrigeration systems characterized by miniaturization, reduced weight, energy savings, and efficient heat transfer, refrigerant composite-enhanced heat transfer can effectively improve the energy efficiency of refrigeration systems, which has been widely studied in recent years. This work summarizes the latest research progress in composite-enhanced flow boiling heat transfer for refrigerants, focusing on nanoparticles, metal foam, external field (ultrasonic/magnetic field/electric field), and environmentally friendly refrigerant mixtures. It also highlights the prospects and existing problems in the application of multi-field synergy and nanoparticle-metal-foam-refrigerant composite-enhanced heat transfer as a future research direction. The review provides insights and references for establishing a new multi-element refrigerant composite-enhanced system.

The increasing global demand for raw materials underscores the importance of lightweight construction and sustainable material use, drawing attention to composite techniques like galvanic coating of plastics. To support recycling efforts, the development of efficient separation and material recovery processes is critical, particularly for end-of-life products containing metal-plated polymers. This study investigates the recyclability of metallized polymer foams and coated polymers through comminution, focusing on the potential for effective separation of metal and polymer components. Cu-ABS samples showed 27% of the products in the 8–10 mm fraction and 48% in the 10–16 mm fraction during primary comminution, while Cu-PUR achieved a more even distribution. Microscopic analyses revealed decoating rates of up to 95% for Cu-ABS compared to 19% for Cu-PUR. The comminution energy required for Cu-PUR was three times higher, with a fivefold lower decoating rate than solid materials. Particles larger than 200 µm exhibited interlocking, complicating the separation process. These findings highlight the need for optimized recycling processes to enable efficient raw material recovery and support a circular economy. [ABSTRACT FROM AUTHOR]

The existing study examines the moisture-dependent vibrational behavior of a metal foam spherical panel that is positioned between two composite layers reinforced with graphene platelets (GPL). The Kerr foundation, a three-parameter elastic foundation, supports the model. Based on specified functionalities, the pores’ arrangement and the GPL dispersion throughout the core and face sheets, respectively, are taken into consideration. The Halpin–Tsai and extended rule of mixture micromechanical models are utilized to ascertain the face sheets’ effective hygromechanical property values. After the motion equations are determined, the frequencies are extracted using the analytical technique, which is particularly effective for shells with simply supported edges. The impacts of various influences on the natural frequencies are considered and addressed over the course of the inquiry. It is shown that natural frequencies drop with increasing porosity coefficient. Furthermore, a small amount of GPL is shown to have a strong reinforcing effect on the stiffness of the structure, hence enhancing natural frequencies. The outcomes of this investigation can be beneficial to a variety of industries such as aerospace, automotive, marine, and civil engineering, where spherical shells are commonly employed. Furthermore, the outcomes might function as a standard for subsequent research. These results not only advance the understanding of moisture effects on composite structures but also provide a foundation for future research aimed at optimizing material properties for specific applications. Additionally, this study offers practical insights for the design and manufacturing of more resilient and efficient spherical components in real-life engineering scenarios. [ABSTRACT FROM AUTHOR]

Using metal foam as a flow field structure is an attractive route to improve the performance of open-cathode PEMFC. Metal foam has shown great potential in improving the uniformity of reactants, but optimized structure parameters that can more effectively transfer gas and remove excess water are needed. Here we experimentally investigate the effect of metal foam structure parameters on cell performance using polarization curves, power density curves, and electrochemical impedance spectrum (EIS) measurements. By optimizing the pore density, thickness, and compression ratio of the metal foam, the performance of the fuel cell is improved by 49.8%, 42.1%, and 7.3%, respectively. The optimum structure value of metal foam is the pore density of 40 PPI, the thickness of 2.4 mm, and the compression ratio of 4:2.4. In this configuration, the cell could achieve a maximum power density of 0.485 W cm−2. The findings of this work are beneficial for the application of metal foams in open-cathode PEMFC. [ABSTRACT FROM AUTHOR]

Metal foams are promising materials for the flow fields of proton exchange membrane fuel cells (PEMFCs) because of excellent mass transport characteristics and high electronic conductivity. To resolve the corrosion problem in the acidic environment under high temperature, nickel/graphene (Ni/G) composite coatings with hierarchical structures were electrodeposited on the surface of Ni foam. The effect of grain size and the distribution in the double layer was discussed. It was found that Ni/G5-10, with larger inner size and middle outer size, exhibited the best corrosion performance. Meanwhile, the corrosion current in the Tafel plots and the steady current density in constant potential analysis was lower than that obtained under steady and gradient currents. Combined with the results of XRD, XPS, and SEM, it was proven that a uniform and dense protective film was produced during the two-step electrodeposition. Moreover, the ICR value was 8.820 mΩ·cm2, which met the requirement of 2025 DOE. [ABSTRACT FROM AUTHOR]

One of the main issues faced in the operation of a metal foam centrifugal breather is the high pressure drop. This study investigates the pressure drop of a metal foam centrifugal breather. The numerical simulation research method is adopted. The DPM model is used to calculate the two-phase flow field of the metal foam breather, and the porous medium model is used to replace the metal foam at the breather. The resistance caused by the metal foam is replaced by a distributed resistance added to the fluid. The effects of flow rate, rotational speed, porosity, PPI (pores per inch), and temperature on the pressure drop of the breather are analyzed. The results indicate that rotational speed, flow rate, porosity, and PPI significantly influence the resistance of the metal foam centrifugal breather. The resistance of the breather is directly proportional to the rotational speed, flow rate, temperature, and metal foam pore density, and inversely proportional to the porosity. Temperature has a minor impact on the resistance of the metal foam centrifugal breather. Therefore, the metal foam centrifugal breather is more suitable for low-speed operating conditions. [ABSTRACT FROM AUTHOR]

Lithium-based battery packs consist of numerous battery cells which form an essential component of electric vehicles. Inadequate heat transfer creates various challenges to safety issues in these batteries. Hence, assessment of the thermal performance of battery packs is an integral part of the design phase. In this study, a numerical approach of the system is implemented using a three-dimensional cylindrical model of a lithium Manganese dioxide battery cell. The model incorporates the application of the metal foam of different geometrical parameters saturated with air for the thermal cooling of batteries. The model considers the cooling phenomenon during discharge process of a cell with a C-rate of 1C respectively. The change in internal resistance of the cell with temperature during the process is estimated using the Generalized Reduced Gradient (GRG) algorithm. The system is considered to be adiabatic by maintaining a flow of liquid through convective tubes, to maintain a constant temperature. The Battery Thermal Management System design is proposed using the Ansys-Fluent software assuming finite volume analysis. The results are analyzed in terms of the maximum battery temperature attained and with the maximum surface temperature of the battery and the metal foams acquired during the process. [ABSTRACT FROM AUTHOR]

Dissipation of heat has become a common reason for the thermal runway and malfunction of various electronic devices. To effectively use these devices, it is mandatory to extract heat from the dissipating parts. Impinging jet flows (IJF) have been used for cooling purposes for decades. The jet impingement technique contains a pressurized fluid and is designed to spray the fluid with the help of a nozzle on the surface of the disc or plate which is being heated. However, recent advances on the effective heat transfer using metal foams are being studied. This research work focuses on the contribution of laminar and turbulent flows from IJF in extracting heat from the surface plate in the presence of geometrically diverse metal foams. The factors under consideration are H/Dj, Heat flux, thickness of the metal foams, and diameter of the metal foams. This research is purely experimental, and the experimental setup consists of mainly compressor, pressure gauges, rotameter, electric resistor, and thermocouples. The flows are controlled through rotameter and are kept in the range of Re from 800 to 2000 for laminar and from 3000 to 23000 for turbulent region. The outcomes of the results are extremely useful in engineering applications and the data can be used to design an effective heat exchanger. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Refrigeration is the property of Journal of Refrigeration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Xi'an Jiaotong University is the property of Editorial Office of Journal of Xi'an Jiaotong University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To address the demands for high-efficiency heat transfer and compact lightweight design in space stations, a high-efficiency condensation dehumidification system utilizing copper foam and driven by a Stirling refrigerator was developed. An experimental study was conducted to investigate its heat and mass transfer characteristics under various conditions. The experimental parameters were set as follows: air inlet temperature ranging from 20 to 30 °C, relative humidity between 50 % and 80 %, cold plate temperature from 8 to 13 °C, and inlet wind speed from 0.4 to 1.4 m/s. The results indicate a positive correlation between the increase in air inlet temperature and the enhancement of both heat transfer coefficient and mass transfer coefficient. Specifically, when the air inlet temperature increased from 20 °C to 30 °C, the heat transfer coefficient rose by 10.5 %, while the mass transfer coefficient exhibited a more substantial increase of 57.1 %. Furthermore, variations in the relative humidity of the air inlet had distinct impacts on the heat and mass transfer coefficients: the heat transfer coefficient decreased with increasing relative humidity, whereas the mass transfer coefficient increased. Notably, although lowering the cold plate temperature can significantly improve heat transfer, it concurrently diminishes the efficiency of heat and mass transfer. Therefore, selecting an appropriate cold plate temperature is crucial. Additionally, the efficiency of heat and mass transfer was markedly enhanced with increasing inlet wind speed; however, a continuous increase in wind speed resulted in higher system energy consumption. Thus, a balance between achieving efficient heat transfer and managing system energy consumption is essential. Based on extensive experimental data, the heat transfer model was refined through regression analysis. The relative average deviation between theoretical and experimental values was found to be 8.97 %, with a relative standard deviation of 8.21 %, demonstrating the model's strong predictive accuracy.

In the present work, the impact of metal foam (MF) on the thermal efficiency of a parabolic trough collector (PTC) was experimentally investigated using two types of receivers: one with metal foam insertion (MFI) and one without. Tests were conducted with a 30% filling ratio (FR) of copper foam blocks, consisting of 10 discs, each 45 mm thick, semi-uniformly spaced along the receiver pipe. The copper foam had pore densities of 10–40 PPI and porosities of 0.903 and 0.8983. The experiments carried out under ASHRAE 93 standards involved varying volume flow rates from 0.1 to 0.3 LPM, using water as the heat transfer fluid. The experiments took place in Iraq in May 2024, from 9:00 a.m. to 4:00 p.m., under solar radiation conditions. To ensure data reliability, uncertainty analyses were performed on temperature, solar irradiation, flow rate, and pressure drop. The results indicated that the use of metal foam in the receiver improved collector efficiency, with a notable 16.74% increase at 40 PPI and 0.3 LPM. The highest thermal efficiency was achieved with 40 PPI, which raised the PTC outlet temperature to 58 °C at 0.1 LPM, compared to 53 °C for a without MFI pipe. According to performance evaluation criteria, 10 PPI foam outperforms 40 PPI foam. Compared to the denser 40 PPI, the larger 10 PPI pores improve water flow, reduce resistance, and require less energy to pump the heat transfer fluid (HTF). However, the findings found that while metal foam improves heat transfer efficiency, it increases pressure drop, highlighting the importance of balancing these factors in system design.

The main task of this work is the optimization of the manufacturing process of Al-alloy lattice cellular structures with rhombic cell, obtained with lost-PLA technique. It is an easy, environment sustainable and economical technique (both for infrastructure and operating costs) for the manufacturing of Al porous structure based on the 3D printing of PLA and replication process alternative to that based on expensive metal 3D printers. Plaster processing, PLA burnout and AA 6082 alloy casting conditions and parameters have been suitably tuned in order to get final samples with geometry and surface finishing conditions identical to the starting ones made in PLA. A good replication process has been implemented with a high repeatability rate and accurate surface finishing, comparable with that of the PLA printed objects. Morphological analysis on PLA and Al 6082 was conducted as well microstructural analysis and Vickers microhardness tests on Al alloy samples in the as-cast conditions. Metallography reveals the presence of AlFeSi and AlFeMnSi intermetallic phases at the cell boundaries and some coarse precipitates Mg2Si in the AA 6082 alloy. Microstructures and HV measured values are aligned with literature data for this alloy in the same (as-cast) conditions.

The two-dimensional numerical simulations focused on fluid flow and heat transfer within a solar air heater (SAH) channel incorporating copper metal foam with a porosity of 90% were carried out in this study. The Local Thermal Non-equilibrium (LTNE) and Darcy-Extended Forchheimer (DEF) models were employed to predict fluid and thermal transport in the partially porous SAH channel. In the free flow zone, the turbulence model was utilized. The thermal and thermo-hydraulic performances of SAH were examined concerning several factors, including pore density ( ), Reynolds number ( ), and dimensionless foam height ( ). The results demonstrate that inserting a porous substrate into the SAH can substantially increase heat transmission. This enhancement ranges from 4.4 to 18.04 times compared to an empty duct for at . Moreover, increased porous layer height and pore density lead to a corresponding increase in pressure drop. Evaluating both the improvement in heat transmission and the associated pressure penalty, the case with , and demonstrate superior overall performance, boasting a higher Thermal Performance Factor ( ) of 2.82 when compared to an empty channel. This work presents significant findings on optimizing metal foam applications in SAH systems, offering new insights into the field.

In this work, theoretical and numerical studies of the dynamic response of a fiber–metal laminate (FML) sandwich beam under uniform blast loading are conducted. On the basis of a modified rigid-plastic material model, the analytical solutions for the maximum deflection and the structural response time of FML sandwich beams with metal foam core are obtained. Finite element analysis is carried out by using ABAQUS software, and the numerical simulations corroborate the analytical predictions effectively. The study further examines the impact of the metal volume fraction, the metal strength factor between the metal layer and the composite material layer, the foam strength factor of the metal foam core to the composite material layer, and the foam density factor on the structural response. Findings reveal that these parameters influence the dynamic response of fiber–metal laminate (FML) sandwich beams to varying degrees. The developed analytical model demonstrates its capability to accurately forecast the dynamic behavior of fiber–metal laminate (FML) sandwich beams under uniform blast loading. The theoretical model in this article is a simplified model and cannot consider details such as damage, debonding, and the influence of layer angles in experiments. It is necessary to establish a refined theoretical model that can consider the microstructure and failure of composite materials in the future. [ABSTRACT FROM AUTHOR]

Metallic foams exhibit unique properties that make them suitable for diverse engineering applications. Accurate mechanical characterization is essential for assessing their performance under both monotonic and cyclic loading conditions. However, despite the advancements, the understanding of cyclic load responses in metallic foams has been limited. This study aims to propose a mesostructural model to assess the fatigue behavior of open-cell metal foams subjected to cyclic loading conditions. The proposed model considers the previous load history and is based on the analogy of progressive collapse, integrating a finite element model, a fatigue analysis model, an equivalent number of cycles model, and a failure criterion model. Validation against experimental data shows that the proposed model can reliably predict the fatigue life of the metallic foams for specific strain amplitudes. [ABSTRACT FROM AUTHOR]

The need for high speed and reduction in size in electronic components leads to a rise in the power dissipation needed for thermal management. In this research, experiments have been carried out to examine the thermal efficiency from heat sink located on an energy source in a channel. A total of 4 test models with different shapes were tested. Model 1 conventional heat sinks is made from aluminum, model 2 fin heat sinks is made from metal foam, model 3 plate heat sink is made from metal foam and model 4 fin heat sinks filled space between the fins with metal foam; all models have the same flat plate surface area. Copper metal foam of constant pore density of 40 PPI and constant porosity of 0.91 were used. The test runs are done at the air flow rates ranging between (1.2 to 3.3) m/s with the inlet air temperature is 27 °C. The outcomes revealed that the model 3 heat sinks have a greater heat transfer coefficient and a lower thermal resistance than the other types of heatsinks. At input velocity of 3.3 m/s and high power of 30 W, model 3 has the best Nusselt number ratio it has increased from models 2 and 4 by 13.7% and 6.8%, respectively. The plate foam heat sink model 3 has a larger pressure drop when compared to conventional fin heat sink model 1. Moreover, the pressure drop between Models 2 and Model 4 is not significantly different. Additionally, at higher flow rates, the model 3 heat sinks show a 22% reduction in thermal resistance compared to the model 1 at a power of 30 W. [ABSTRACT FROM AUTHOR]

The main task of this work is the optimization of the manufacturing process of Al-alloy lattice cellular structures with rhombic cell, obtained with lost-PLA technique. It is an easy, environment sustainable and economical technique (both for infrastructure and operating costs) for the manufacturing of Al porous structure based on the 3D printing of PLA and replication process alternative to that based on expensive metal 3D printers. Plaster processing, PLA burnout and AA 6082 alloy casting conditions and parameters have been suitably tuned in order to get final samples with geometry and surface finishing conditions identical to the starting ones made in PLA. A good replication process has been implemented with a high repeatability rate and accurate surface finishing, comparable with that of the PLA printed objects. Morphological analysis on PLA and Al 6082 was conducted as well microstructural analysis and Vickers microhardness tests on Al alloy samples in the as-cast conditions. Metallography reveals the presence of AlFeSi and AlFeMnSi intermetallic phases at the cell boundaries and some coarse precipitates Mg2Si in the AA 6082 alloy. Microstructures and HV measured values are aligned with literature data for this alloy in the same (as-cast) conditions. [ABSTRACT FROM AUTHOR]

High output temperature and photothermal conversion effectiveness were achieved with the absorber platform structure. A novel solar receiver was manufactured to integrate pre-heating and thermal conversion, aiming to enhance heat utilization and output temperature. This work is based on the engineering design and experimental testing of a solar cavity-receiver containing a porous copper foam that can volumetrically absorb high-flux radiation and heat up, through convection with air-flow. The air outlet temperature, outer wall temperature, thermal performance, and efficiency were experimentally determined by pore density, air mass-flow rate and solar irradiance. Additionally, the temperature growth of unit incident power, the unit volume efficiency growth rate, and output temperature were employed to evaluate the thermal conversion characteristics of the endothermic body (copper foam). The results indicated that the air outlet temperatures can reach 500 °C with lower input power. Furthermore, it was found that under a pore density of 30 pores per inch and a flow rate of 60 Lpm, the photothermal conversion efficiency of the absorber with copper foam reached as high as 87.61%, which is 35.04% significantly higher than that of an absorber without copper foam. The manageable solar receiver design proved to deliver a high-temperature air-flow (approximately 500 °C) with a reasonably high thermal efficiency (over 85%). [ABSTRACT FROM AUTHOR]

Porous copper (Cu), with varying porosities, has been made using carbamide as a space holder through the powder metallurgy route. Two shapes of carbamide particles were used, (i) needlelike and (ii) spherical, in order to investigate the effect of the space holder shape on the pore structure and mechanical properties of porous Cu. The compressive deformation behavior of porous Cu was studied under a compression test. The pores' structural characteristics and mechanical properties of the porous Cu varied significantly with the shape of the space holder. Although the effect of the space holder shape on the porosity was not regular, the effect on the mechanical properties was regular. The stress increased monotonically with the increase in the strain, and strain hardening occurred at the plastic yield stage. The elastic modulus and yield strength followed the power law, with the relative density irrespective of the space holder shape. The empirical constants associated with different empirically developed power law relations were different, according to the shape of space holder. A quantitative relationship between the elastic modulus and yield strength and the spacer content was obtained to control the mechanical properties of the present porous Cu or other porous metals and metal foams using the well-known space holder method. [ABSTRACT FROM AUTHOR]

A 2D numerical analysis was conducted to examine the melting performance of a shell-and-tube-type phase change material with a two-layer copper foam having higher and lower porosity levels. The design parameters for these two layers of metal foam consisted of three different volume fill ratios (VFR) (30 %/70 %, 50 %/50 %, and 70 %/30 %) and three different shapes (circular, semi-circular, and elliptical) for the lower porosity layer. The results showed that a semicircular-shaped low porosity layer with a 30 % VFR had the least melting time of 475 s. When the VFR increased to 50 %, the elliptical and circular shapes had the least melting time of 394 s. However, at a VFR of 70 %, only the elliptical shape had the least melting time of 323 s. Furthermore, the results were compared with the uniform porosity metal foam system, and deduced that the two-layer system did not always have the lower melting time compared with that of the uniform porosity system because it depended on the VFR and shape of the different porosities filled in the different layers. Additionally, for an average porosity of the metal foam, an optimal combination of two different porosities was observed for the melting performance.

With the development of surface engineering, porous surfaces have emerged as a significant research subject in boiling heat transfer. The latter, in turn, plays a crucial role in various industries such as power plants, distillation plants, and microelectronic technology. In this paper, the Molecular Dynamics method is adopted to investigate the wicking dynamics and boiling dynamics of two porous surfaces: foam, which exhibits randomly distributed pores, and mesh, composed of ordered square wires with relatively uniform pore sizes. Three wettability, namely hydrophilic, neutral, and hydrophobic wetting states, are assigned to the two porous surfaces de-coupling the effect of wettability from surface structure. Results reveal that, during the wicking process, the foam surface shows better wetting ability as it absorbs liquid under both hydrophilic and neutral wettability. Comparatively, the mesh surface has the fastest wicking speed under hydrophilic wettability yet it becomes non-wetting under neutral wettability. During the boiling process, the boiling dynamics differ greatly under three wettability. More importantly, the difference in surface structure makes the foam surface possess a better heat transfer whereas the mesh surface causes gentle pressure variation. Our findings provide insights into the design of artificial porous surfaces for certain purpose and their potential application.

Abstract A solid substance encircled by a three-dimensional network of voids not interconnected with each other is referred to as close-cell metal foam. The work is based on enhancing mechanical properties of aluminum base close-cell metal foam through the addition of reinforcing particles in varying percentages. Closed-cell aluminum foams with the addition of Mn (0.5 wt.%) and Mg (0, 1, 1.5, 2) were successfully prepared by the melt route method. Al-based metal foam’s morphology and mechanical behavior were examined in order to understand the impact of reinforcing elements. From the current work, it is inferred that the addition of reinforcing elements initially helped to increase the compressive strength as found in Foam-1, but further addition of Mg did not have any beneficial effects. It was found that the value of compression strength depends on foam density. The addition of reinforcing elements increases the length of the plateau which in turn increases the value of energy absorption. It is found that proper bonding of reinforcing particles helps in improving energy absorption. From the evaluation, it was found that besides the increase in density and variations in pores uniformity, Al + Mn (0.5wt. %) + Mg (1.5wt. %) Foam (Foam-1) was found to be superior among all other foams. It can also be concluded that by fixing the percentage of Mn by 1 wt%, the best results can be obtained by addition of 1.5 wt. % Mg in the melt. Further addition of Mg shows a detrimental effect on mechanical and physical properties.

The aim of the present research work is to understand the intricacies of fluid flow through a rectangular channel that has been partially filled with a metal foam block of different blockage ratio (0.16-1), with a pore density (5–30 Pores Per Inch i.e. PPI), along with varying inlet velocity (6.5–12.5 m/s). For the porous region, numerical solutions are acquired using the Darcy Extended Forchheimer model. The Navier-Stokes equation is used in the non-porous zone. Different flow behaviours were seen as a function of PPI, height, and inlet velocity. The pressure drop increases with inlet velocity, PPI, and block height, with a maximum value of approximately 4.5 kPa for the case of 30 PPI, 12.5 m/s, and a blockage ratio of 1. Results show that the existence and location of the formation of eddies depends on the inlet velocity, PPI, and blockage ratio. Such studies have been reported less and will aid research on forced convection through a channel partially filled with metal foam and optimisation studies between increased heat transmission and the additional pressure drop for the same by providing a detailed fluid flow analysis.

The increasing global demand for raw materials underscores the importance of lightweight construction and sustainable material use, drawing attention to composite techniques like galvanic coating of plastics. To support recycling efforts, the development of efficient separation and material recovery processes is critical, particularly for end-of-life products containing metal-plated polymers. This study investigates the recyclability of metallized polymer foams and coated polymers through comminution, focusing on the potential for effective separation of metal and polymer components. Cu-ABS samples showed 27% of the products in the 8–10 mm fraction and 48% in the 10–16 mm fraction during primary comminution, while Cu-PUR achieved a more even distribution. Microscopic analyses revealed decoating rates of up to 95% for Cu-ABS compared to 19% for Cu-PUR. The comminution energy required for Cu-PUR was three times higher, with a fivefold lower decoating rate than solid materials. Particles larger than 200 µm exhibited interlocking, complicating the separation process. These findings highlight the need for optimized recycling processes to enable efficient raw material recovery and support a circular economy.

One of the main issues faced in the operation of a metal foam centrifugal breather is the high pressure drop. This study investigates the pressure drop of a metal foam centrifugal breather. The numerical simulation research method is adopted. The DPM model is used to calculate the two-phase flow field of the metal foam breather, and the porous medium model is used to replace the metal foam at the breather. The resistance caused by the metal foam is replaced by a distributed resistance added to the fluid. The effects of flow rate, rotational speed, porosity, PPI (pores per inch), and temperature on the pressure drop of the breather are analyzed. The results indicate that rotational speed, flow rate, porosity, and PPI significantly influence the resistance of the metal foam centrifugal breather. The resistance of the breather is directly proportional to the rotational speed, flow rate, temperature, and metal foam pore density, and inversely proportional to the porosity. Temperature has a minor impact on the resistance of the metal foam centrifugal breather. Therefore, the metal foam centrifugal breather is more suitable for low-speed operating conditions.

The use of Phase Change Materials (PCMs) for latent thermal energy storage enhances the availability of solar energy. PCMs can store a large amount of energy in a small volume using almost entirely isothermal processes. Despite this, the poor thermal conductivity of PCMs is a significant disadvantage of current PCMs, severely limiting their energy storage capabilities. As a result, the solidification/melting rates are reduced to an unacceptable level, and the system reaction time is increased unreasonably. By combining the novel fin arrangement, nanoparticles, and metal foam, the current study improved the solidification rate of the PCM in the Latent Heat Thermal Energy Storage System (LHTESS). LHTESS was numerically evaluated in ANSYS Fluent 18.1 using a solidification and melting model. The addition of cesaro fins, nanoparticles, and metal foam significantly improved PCM solidification in the LHTESS. PCM solidification time was reduced by 42.42% and 39.39% in Type-3 and Type-5 fin configurations, respectively, when compared to Type-4 fin configuration. Furthermore, a temperature difference of 27 K between the Heat Thermal Fluid (HTF) and the PCM ensures the best solidification performance. By incorporating nanoparticles into PCM and metal foam, the solidification time is reduced by 73.68%. Depending on the foam structure and volume fraction of the nanoparticles, dispersing nanoparticles in PCM with metal foam saves up to 75% of the time.

A natural convection heat transfer inside rhombic square cavity partially filled with porous material have been numerically investigated. A constant heat flux has been applied to the left wall with a right wall kept in constant cold temperature while thermally insulated the top and bottom walls. Finite volume technique with Simple algorithm have been used to simulate the governing equations of fluid flow and heat transfer coupled with Darcy-Brinkman model to simulate the flow of the air inside the main cavity and the open cells of the porous media. Three factors were chosen to study their effects on the natural air velocity and the mechanism of the free convection inside the enclosure. The inclined angle of the sidewall of the rhombic (q = 90o, 80o and 70o), the thickness of the metal foam (t = 5 cm, 10 cm, and 15 cm) and the amount of heat flux (q = 150 to 600 w/m2). Copper metal foam with 0.9 porosity was chosen as porous media with open cell filled by air (Prandtl number =0.7) and 10 as pore density. The results showed that using a layer of porous metal foam with open cells will increase the heat transfer rate. It was 41.3% enhancement when use 5 cm of porous media and 68% for 15 cm. Acute inclined angle will decrease local Nusselt number and led to form vorticities. Furthermore, high heat flux increased the average Nusselt number and improved the heat transfer rate.

The improvement in solar chimneys' thermal performance and thermal behavior that can be achieved by adding metal foam has been tested in computational work. The flow and heat transfer governing equations for solar chimney models were solved using computational fluid dynamics (CFD). It was solved using the control volume numerical method in ANSYS FLUENT 14.5. It is used to construct a finite volume modeling technique for solving the governing equations and the radiation heat transfer equations. With standard flat absorber plates, the results showed that heat transmission was increased by the inclusion of metal foam (10 PPI), leading to an increase in air velocity at the solar chimney of around 13.3%. The highest average air velocity with 10 PPI drops by 54.4% as the height of the absorber plate changes from 5 cm to 25 cm respectively.

The aim of the present research work is to understand the intricacies of fluid flow through a rectangular channel that has been partially filled with a metal foam block of different blockage ratio (0.16-1), with a pore density (5-30 Pores Per Inch i.e. PPI), along with varying inlet velocity (6.5-12.5 m/s). For the porous region, numerical solutions are acquired using the Darcy Extended Forchheimer model. The Navier-Stokes equation is used in the non-porous zone. Different flow behaviours were seen as a function of PPI, height, and inlet velocity. The pressure drop increases with inlet velocity, PPI, and block height, with a maximum value of approximately 4.5 kPa for the case of 30 PPI, 12.5 m/s, and a blockage ratio of 1. Results show that the existence and location of the formation of eddies depends on the inlet velocity, PPI, and blockage ratio. Such studies have been reported less and will aid research on forced convection through a channel partially filled with metal foam and optimisation studies between increased heat transmission and the additional pressure drop for the same by providing a detailed fluid flow analysis. [ABSTRACT FROM AUTHOR]

Protective steel doors are widely used in buildings due to their high resistance against the impact loads. However, its heavy weight has been always considered as a major drawback for these doors. In this paper, a new optimized stiffened impact-protective steel door incorporating sandwich panel with aluminum foam core (OSSA) is examined. This door consists of two face sheets, main and secondary stiffeners, and aluminum foam as the inner core. In order to optimize the door, at first the rigidity and weight functions of the stiffened steel door were extracted. Then an optimal door weighing 42% less than the primary door was obtained. Due to the high energy absorption capacity of the combined foam core and stiffened steel door structure, the use of aluminum foam core in the optimized steel door was proposed. By doing numerical analysis, and depending on the thickness of the face sheet of OSSA, 20 to 32% reduction in the maximum displacement was observed. The results also showed that, with 67% increase in the peak overpressure, OSSA has kept almost the same maximum displacement as that of the steel door without an aluminum foam. In other words, by using aluminum foam core in the optimized stiffened door, the door will resist 67% more impact load. [ABSTRACT FROM AUTHOR]

A solid substance encircled by a three-dimensional network of voids not interconnected with each other is referred to as close-cell metal foam. The work is based on enhancing mechanical properties of aluminum base close-cell metal foam through the addition of reinforcing particles in varying percentages. Closed-cell aluminum foams with the addition of Mn (0.5 wt.%) and Mg (0, 1, 1.5, 2) were successfully prepared by the melt route method. Al-based metal foam's morphology and mechanical behavior were examined in order to understand the impact of reinforcing elements. From the current work, it is inferred that the addition of reinforcing elements initially helped to increase the compressive strength as found in Foam-1, but further addition of Mg did not have any beneficial effects. It was found that the value of compression strength depends on foam density. The addition of reinforcing elements increases the length of the plateau which in turn increases the value of energy absorption. It is found that proper bonding of reinforcing particles helps in improving energy absorption. From the evaluation, it was found that besides the increase in density and variations in pores uniformity, Al + Mn (0.5wt. %) + Mg (1.5wt. %) Foam (Foam-1) was found to be superior among all other foams. It can also be concluded that by fixing the percentage of Mn by 1 wt%, the best results can be obtained by addition of 1.5 wt. % Mg in the melt. Further addition of Mg shows a detrimental effect on mechanical and physical properties. [ABSTRACT FROM AUTHOR]